<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .fa{
            display: flex;
            width: 640px;
            height: 360px;
            background: url(../img/obt.jpg);
            margin: 0 auto;
        }
        .left,.right{
            width: 50%;
            height: 360px;
            background: url(../img/obt1.jpg);
            transition: all 2s;
        }
        .right{
            background-position: right 0;
        }
        .fa:hover .left{
            transform: translate(-100%)
        }
        .fa:hover .right{
            transform: translate(100%)
        }
    </style>
</head>
<body>
    <div class="fa">
        <div class="left"></div>
        <div class="right"></div>
    </div>
</body>
</html>